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Saturday, December 1, 2007

Getting Vertical


Vertically Challenged • Maximum Quality Formula? • A Little Night Action • Filtering The Sky • Park Photo Permits

Filtering The Sky
I’m having trouble with color variances across the sky portion of my photos when using a circular polarizer. I shoot with a Canon EOS 30D and Canon 17-85mm lens. Most of the time, when I adjust the filter for deep blue sky, one side or the other, a corner or even the center of the frame is darkened. I usually don’t notice the problem until the images are downloaded onto my computer. It’s rare that I get a photo where the whole sky is the same hue, side to side, top to bottom, regardless of the position of the sun. Could it be that I need to use a slim filter or a larger diameter filter with this Canon lens?
Scott T.
Via the Internet


What you’re experiencing isn’t vignetting, where you might need a thinner polarizer or a larger-diameter polarizer. In that case, you’d see a dark shadow in the four corners of the image, no matter what the subject.

One of the problems with polarizing an open sky using a wide-angle lens is that the angle to the sun varies so much within the image that there almost always will be a variance in the amount of polarization across the sky. I find that it’s better to photograph without the filter and simulate the polarization in the computer.

There are times when a polarizer is still a good idea on a wide-angle. When photographing foliage, water or other shiny surfaces, the polarizer saturates the color by eliminating reflections. Another use of the polarizer is when you need to extend exposure, such as for rendering water with a silky texture. The polarizer works as a neutral-density filter, cutting exposure by about two stops of light.

Park Photo Permits

I’m an amateur freelance photographer, especially interested in wildlife. I’m planning a vacation to Rocky Mountain National Park in Colorado. I was told that I couldn’t take pictures of wildlife, etc. and sell them unless I had paid for a permit. My understanding was that if you pay admission, such as a park fee, then you could take pictures and sell them. Do I need a permit or not?
D. Hernandez
Alamogordo, New Mexico


As long as you’re using the national park in the same way as any other visitor, you don’t need any permits to photograph, whether or not you plan to market the images. If you come into the park with a crew to take commercial still or motion-picture images, you definitely need a permit. This critical difference is usually the source of misinformation such as you received.

A directive from the Office of the Secretary of the Interior titled "Commercial Still Photography" states, "It is the policy of the National Park Service to permit and encourage photography within the National Park System to the fullest extent possible consistent with the protection of resources and the enjoyment of visitors." The directive continues, "Permits can be required when the photography involves product or service advertisement or the use of models, sets, props, or when such photography could result in damage to the resources or significant disruption of normal visitor uses."

Policies for other public lands, such as those held by counties and states or controlled by different federal agencies, often vary, reflecting the philosophies or priorities of the administering agency. Some photographers operate under the assumption that it’s easier to ask forgiveness than to get permission, an attitude that typically results in restricted access for those who follow. It’s always best to research the requirements for access to any public land before you arrive.

For information about upcoming seminars and digital-imaging workshops, visit www.geolepp.com. If you have any tips or questions, address them to: OUTDOOR PHOTOGRAPHER, Dept TT, George Lepp, 12121 Wilshire Blvd., Suite 1200, Los Angeles, CA 90025-1176 or online at www.geolepp.com.


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